PET/polyester recycling: requirements and recycling solutions for reuse in filaments

摘要

The EU Waste Framework Directive 2008/98/EC defines recycling as "any recovery operation by which waste materials are reprocessed into products, materials or substances whether for the original or other purposes". Ideally, recycled plastics are reused for the same application as the original product, e.g. PET bottles become PET bottles once more, hence the term bottle-to-bottle recycling. Besides this ideal of a circular economy, the industry differentiates between 2 types of recycling, namely upcycling and down-cycling. Whereas upcycling is defined as the recycling of materials for reuse in high-end applications (in the context here, this would be polyester continuous filament as used in e.g. fabric for car seats, car interiors and active and outdoor wear), downcycling is defined as the recycling of materials for reuse in applications that are considered to be of lower value than the original product, as in the case of polyester staple fiber (used in e.g. soft toys, filling materials or upholstery). The following sections will cover mechanical recycling options for upcycling of both PET and polyester for reuse in the production of polyester continuous filaments.